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Police use a water cannon against protesters during a demonstration in downtown Cairo Tuesday. Thousands of anti-government protesters, some hurling rocks and climbing atop an armored police truck, clashed with riot police Tuesday in the center of Cairo in a Tunisia-inspired demonstration to demand the end of Hosni Mubarak's nearly 30 years in power.

It was reminiscent of Iran’s Green movement protests in 2009. Protesters flooded Cairo’s main squares and Twitter, Facebook, Youtube, and Flickr flooded the Internet with updates. Supporters of Egypt's protesters around the world spread information in updates so rapid and numerous that the collective coverage could probably be classified as viral.